Extrusion press



,July 1l, 1939. A, KRElDLER 2,165,711

EXTRUSION PRESS Filed oct. 31, 19:55

Jgf We @ya 1610746 K 19.5 411376 APatented July 11, 1939 g UN1TED STATESPATENT OFFICE y 'EXTRUSION PRESS Alfred Kreidler, Stuttgart, GermanyApplication October 31, 1935, Serial No. 48.554 In Germany October 31,1934 4 Claims.

This invention relates to improvements in extrusion presses.

' In such presses, especially for producing metallic bodies byextrusion, a great quantity of waste 5 is produced in as much as thesuperiicial layer of the' ingots, which is usually contaminated ordeteriorated by oxides, evaporations or blow holes,

`accumulates before the plunger and is admixed to the extruded materialtowards the end ofv the l0 pressing operation. Hereby a certain portionof the pressed ware is infectedv with a-relatively small impure interiorzone and on this account must be thrown away as waste. The wasteofvaluable material produced by this relatively small core of infectedmaterial is considerable.

In order to separate the contaminated outer layer from thenon-contaminated part of the ingot it has been proposed to use apressing head having a smaller diameter than the receiver (and theingot) so that the outer layer is left behind in the receiver in form ofa sleeve. In this case the head has no guide in the receiver over alength at least equal to the length of the sleeve, and on this accountit; often happened that the head as- -15 sumed an eccentric position inthe receiver so rying out the same by which tfe material of the outerlayer of the ingot contaminated by oxides, evaporations or the like ordeteriorated by blow- 40 holes is substantiallyor wholly prevented fromiiowing into the core. This is attained'by inserting before the headyofthe plunger a foredisk having a smaller cross-section or diameter.

than, the receiver, whereby the contaminated material ofthe heated ingotis separated from.v the material of the non-contaminated core of theingot and islmade to iiow in a plastic state over the edge of thefore-disk. The material thus separated by the fore-disk is conducted.behind y the same and is collected in the space between the fore-'diskand the plunger.' I-Iereby the materialof the contaminated outer zone isprevented from accumulating in front of the fore- 55 disk, then owinginto the stream-line of the resistance to the following material.

(Cl. Zivi-2) non-contaminated material of the core, and therebycontaminating the final product.

To improve the result of this method the foredisk is preferably heatedbefore or/andA during the pressing operation to a temperature higher 5than that \of the pressing head and accommodated to or approaching thatof rthe ingot. In

. some cases a further highly heated disk may be inserted before thepressing head so that the separated contaminated material is carriedbel0 tween well tempered parts to prevent its rapid solidification. Thisexpedient is of especial importance because when omitting itthe materialaccumulating behind the fore-disk would harden between two cooldisks andoffer an enormous 15 The insertion of a thin highly heated vdisk beforethe pressing head is advantageous because the head itself when heated tothe same temperature as the fore-#disk would not withstand the'pressure20 to be applied.

The difference between the radius or crosssection of the fore-disk andthe inner radius or cross-section of the receiver should be accommodatedto the number, shape and cross-section of the matrices, to the pressureto be applied and to the thickness of the contaminated outer layer ofthe ingot. 'I'his difference must at least be approximately equal ormust be superior to the thickness of -the impure outer layer of theingot a0 (before or during the pressing operation).

The invention will now be more fully described in connection with theannexed drawing of which- Fig. l is partly an elevation, partly avertical longitudinal cross-section of a device for carrying 'outtheinvention; 4

Fig. 2 is a similar view showing the fore-disk and part of the ingot incross-section at the beginning of the pressing operation; 40

Fig. 3 is a co responding view showing the`device at the end f theoperation;

Fig. 4 i1: a view, partly in cross-section, showing the fore-diskembedded into a cavity inthe pressing head, and means for advancing theforedisk with greater speed than the pressing head;

Figs. 5 to 'l show modications in shape of the fore-disk or the pressinghead;

Fig. 8 is on a reduced scale, a cross-sectional View showing anextrusion press provided with the implement shown in Fig. 4.

In Figs. l to 3 I4 is the walliof a receiver, 2 is tbe matrixthroughwhich the rod or stick 3 is pressed out of the heatedingot 4. 5 is theplunger of a hydraulic or other press moving in the bore disk 9 carriesstud loosely engaging the bore 9. For extruding the plastic materialfrom the ingot 4 the plunger is advanced in the direction of the arrowP. h

Fig. i shows the position of the single parts in the beginning of thepressing operation, the annular space l2 included between the rear faceof member 9, the wall I and the front face of the head 1 still beingempty. Fig. 2 shows the position of the parts at the beginning, and Fig.3 illustrates the position at the end oi the pressing operation.

The device operates as follows: By advancing the parts 1 and 9 at firstthe space I2 is filled with metal cut out, as it were, from the ingot 4by the edge of the disk 9. Hereby the impure oter layer of the ingot isseparated from the valuable material of the interior of the ingot andremoved rearwards behind the front face of part 9. The impure materialis, so to speak, wound up in the space I2, as indicated at I3 in Figs. 2and 3. On further continuing the pressing operation, the lines of flowdammed at the pressing disk are continuously separated by the fore-disk9 intoflines indicating the way of the non-contaminated and linesindicating the way of the contaminated material, the latter being, so tospeak, cut ofi from the pure core-portion and collected in the space I2.According to the volume of the metal received the fungiform disk 9retires from the head 9 whereby'the space |2 automatically increases.During this movement the stud Il is guided by the bore 8 of the head 1 fso that the disk 9 is always equally spaced from the wall I.

Thus the disk 9, so to speak, intercalates itsel 1 into the ow of theplastic material 4; it does not change by force the direction of theilow, but flows, as it were, along with the metal flow, merelyseparating the contaminated outer vlayer from the valuable core of theingot 9 by intervening between them. At the end of the pressingoperation the whole of the contaminated outer layer of the ingot 4 has,as it were, wound itself up behind the fungiform disk 9 in the enlargedspace I2, as shown in Fig. 3 at I3, whereasonly valuable material, i.e., material free from blowholes, has vbeen extruded to form the stick3.

Fig. 4 shows a modiilcation in which the disk 9* is initiallycountersunk in acavity 2* of the r The disk 9* is carried by a secondplunger I4 which is mechanically advanced in the direction of thearrow.P. The plunger4 |4 may be actuated hydraulically in the sameggivayas the plunger 9 by means oli-a cylinder containing a piston orotherwise The single parts of this modification may also be carried outin accordance with the other modifications shown. As Y The operation ofthe modification shown iny Fig. 4 is as follows: y

After the ingot 4 has been introduced into the l bore 9 of the receiver,the plunger 5 forces the head 1* forward, the latter taking along withit the disk 9*. Immediately after the beginning of the pressingoperation the plunger |,4 begins to go videdwith vaulted cavities I5whereby the winding up of the outer layer of the ingot 4 in the spaceI2b is facilitated. The delineation substantially corresponds to that ofFigs. 1 to 4, 'but it is understood that the vaulted cavities may alsobe employed in connection with the other modiflcations shown. In somecases it suilices to provide vaulted cavities in the head 1 only.

In Fig. 6 the iront edge I6 of the disk 9 is shaped to form a wedge orknife to attain a sharp separation between the ilow of the bad outerlayer and the valuable core of the ingot 4, the iiow of the valuablecore being indicated by dotted lines. 1c is the lead. The wedge-likeedge of the disk 9? may be advantageously employed in connection withthe other modiilcations shown.

In Fig. '7 a disk I1 is placed before the head 1d before introducing thefungiform disk 9d with its stud ||d into the bore of the head 1d. Thedisks I1 and 9d are introduced into the receiver in a highly heatedstate, as mentioned before. This measure may also be applied to themodiiications illustrated in Figs. Lto 6. i

l Fig. 8 is a diagram showing a hydraulic press equipped with theimplement illustrated in Fig. 4. Reference letters I to 1, 1*, 9*, I2*and i4 designate the same parts as in Fig. 4. The cylinder I4, becausethe disk 9 contacts with the head 1".

This movement is not prevented by the link-work 20, 2|, 22, 23 to bedescribed hereafter.

The plunger I4 carries at its rear end a guiding piece 24 adapted toslide in the axial bore 25 of the piston I9. A double-armed lever 20, 2|is linked to the said piece 24 at 26 by a swing arm 22. The lever 29, 2|is fulcrumed in a projection 21 of the piston I9. The other end of thelever 20, 2| cooperates with an arm 23 fulcrumed at a point 29 ilxed onthe frame of the press. This arm 23 is provided with a longitudinal slot29 which is located horizcntally during the ilrst half of stroke of thepiston, so that, as already mentioned, the disk 9* is not iniluenced bythe linkwork in the meantime, the double-armed lever 29, 2| moving byits pivot with the piston I9 without anyrrotation around this pivot,because the free end of its arm 2| then freely slides in the horizontalslot 29 of the arm 23.'

After the iirst half pf the stroke has been nished, the arm 2| strikeswith its end 39 guided in the slot 29 on the `substantially horizontalarm 23 atthe end ofthe slot and is thereby retained. From this momentthe double-armed lever 29, 2| is turned aroun'd its pivot while thestroke of the head 1a is continued. whereby the disk 9a goes in advanceof the head 1a according to the position of the iulcrum of the lever 2l,2|.

If it is desired to make the disk 9a advance already at a prior point'oithe stroke, the slot is shortened at its end turned towards the xedfulcrum 28 ofgthe arm 3l which may easily be ef-` fected bygmeans of aset-screw.

The invention is also applicable' to the socalled reversed extrusionprocess in which the matrix is moved towards the ingot and exerts thepressureon it, whereas the rear end of the receiver is closed.

r I claim:

1. In an extrusion press a receiver, a piston closing one end of thereceiver, an extrusion die at the other end of the receiver, a loosedisk between the piston and the die of such diameter that the volume ofthe space between disk and :piston when the two are in contact isconsider- 1 ably exceeded by the volume of a body having the length ofthe stroke and being bounded by an outer cylinder having the diameter ofthe receiver and an inner cylinder having the diameter of the said disk,and means for guiding the said disk in the piston, whereby on advancingthe piston the contaminated metal is gradually forced into the spacebetween the disk and the piston and after this space has been filled thedisk is caused to move along with the extruded metal.

2. In 'an extrusion press a receiver, a piston comprising a plunger anda head piece closing one end of the receiver, an extrusion die at theother end of the receiver, a loose disk between the piston and the dieof such diameter that the volume of the space between disk and pistonwhen the two are in contact is considerably exceeded by the volume of abody having the length of the stroke and being bounded by an outercylinder having the diameter of the receiver and an inner cylinderhaving the diameter of the said disk, and means for guiding the saiddisk in the piston, whereby on advancing the piston the contaminatedmetal is gradually forced into the space between the disk and the pistonand after this space has been lled the disk is caused to move along withthe extruded metal.

3. In-an extrusion press a receiver, a piston closingone end of thereceiver, an extrusion die' piston when the two are in contact isconsiderably exceeded by the volume of a body having the length of thestroke and being bounded by an outer cylinder having the diameter of thereceiver and an inner cylinder having the diameter of the said disk, anda plunger integral with the said disk guided in a corresponding bore ofthe piston, whereby on advancing the piston the contaminated metal isgradually forced into the space between the disk and the piston andafter this space has been filled the disk is caused to move along withthe yextruded metal.

4. In an extrusion press a receiver, a piston closing one end of thereceiver, an extrusion die at the other end of the receiver, a loosedisk between the piston and the die of such diameter that the volume ofthe space between disk and l to receive also the disk, whereby onadvancing the piston the contaminated metal is gradually lforced intothe space between the disk and the piston .and after this. space hasbeen iilled the disk is caused. to move along with the extruded metal. l

ALFRED KREIDLER.

